Image formation apparatus

ABSTRACT

An image formation apparatus comprises: an automatic adjustment unit for automatic adjustment of the apparatus; a job queuing unit for queuing image formation jobs; a counting unit for counting the number of pages from the previous automatic adjustment, for each automatic adjustment item; a determining unit for determining whether the number of image formation pages for automatic adjustment will be reached during execution of the image formation queued job; and a control unit wherein, in the event that the determining unit determines that the number of image formation pages for automatic adjustment will be reached during execution of the image formation job queued by the job queuing unit, automatic adjustment is performed before starting executing of the image formation queued job even though the number of image formation pages counted by the counting unit has not reached the number for the automatic adjustment is to be performed.

This is a divisional of U.S. patent application Ser. No. 10/691,516,filed Oct. 24, 2003, now pending.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image formation apparatus havingfunctions for automatic adjustment or maintenance.

2. Description of the Related Art

In some cases, these types of conventional image formation apparatuseshave a problem in that image density changes due to the change in aphotosensitive member and a developing device over time, or due to thechange in the temperature or humidity in the environment where theapparatus has been situated. As a countermeasure for the above-describedproblem, various proposals have been made with regard to a techniquewherein parameters having an influence upon the image density of a tonerimage, e.g., a charging bias, a developing bias, and so forth, areadjusted at a suitable timing, thereby stabilizing the image density.For example, in a case of forming a color image using multiple imagecarrying members, a method of controlling toner density (Japanese PatentLaid-Open No. 63-147177), and a method of controlling an exposure amount(Japanese Patent Laid-Open No. 63-280275, are known wherein control isperformed based upon detected information with regard to a predeterminedpattern (test patch) transferred onto transfer means such as a commontransfer belt or the like for transferring each visible image on theimage carrying member onto a transfer member.

Furthermore, a method is known wherein the aforementioned test patch istransferred onto the transfer means, the density thereof is measured,and one of multiple process parameters relating to the image formationmeans is adjusted based thereupon (Japanese Patent Laid-Open No.63-43169). Furthermore, a method is known wherein exposure is made withvarious exposure amount in the range corresponding to the change in thelight-portion potential estimated from the change in the environment,and the light-portion potential, which is to be a standard maximaldensity, is estimated based upon the pattern formed of the portions ofdifferent light-portion potential transferred onto the transfer means(Japanese Patent Laid-Open No. 1-261668). Furthermore, in addition tothe above-described, a method is known wherein the change in the size ofone dot is measured from the positional deviation of the pattern on thetransfer means, and the process parameters such as an exposure period,output, a developing bias, and the like, are adjusted based upon themeasurement results so as to maintain the suitable size of one dot(Japanese Patent Laid-Open No. 63-280275).

However, the above-described conventional image formation apparatuseshave a problem in that in the event that the total count reaches apredetermined threshold number during processing, even for a job havingjust a few copies, the image formation apparatus enters an adjustmentmode such as a density adjustment mode, leading to a problem of increaseof time for processing the jobs beyond the anticipation of the user.There has also been a problem in that in the event that the imageformation apparatus enters an adjustment mode, the tone or the like ofthe image formed may not be the same before and after the adjustment.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image formationapparatus to solve the above-described problems.

To this end, according to a first aspect of the present invention, animage formation apparatus for forming images based on input image datacomprises: an automatic adjustment unit for performing automaticadjustment of the image formation apparatus; a job queuing unit forqueuing image formation jobs; a counting unit for counting the number ofimage formation pages from the previous automatic adjustment, for eachautomatic adjustment item which the automatic adjustment unit performs;a determining unit for determining whether or not the number of imageformation pages at which the automatic adjustment is to be performed bythe automatic adjustment unit will be reached during execution of theimage formation job queued by the job queuing unit, based on the numberof image formation pages counted by the counting unit and the imageformation job queued by the job queuing unit; and a control unitwherein, in the event that the determining unit determines that thenumber of image formation pages at which the automatic adjustment is tobe performed by the automatic adjustment unit will be reached duringexecution of the image formation job queued by the job queuing unit,automatic adjustment is performed by the automatic adjustment unitbefore starting executing of the image formation job queued by the jobqueuing unit even though the number of image formation pages counted bythe counting unit has not reached the number at which the automaticadjustment is to be performed by the automatic adjustment unit.

According to a second aspect of the present invention, an imageformation apparatus for forming images based on input image datacomprises: an automatic adjustment unit for performing automaticadjustment of the image formation apparatus; a counting unit forcounting the number of image formation pages from the previous automaticadjustment, for each automatic adjustment item which the automaticadjustment unit performs; a control unit for effecting automaticadjustment by an automatic adjustment unit, in response to the number ofimage formation pages counted by the counting unit reaching a firstthreshold value; a setting unit for setting a second threshold valuesmaller than the first threshold value; and a determining unit fordetermining whether or not the number of image formation pages countedby the counting unit have reached the second threshold value set by thesetting unit before starting execution of the next image formation job;wherein, in the event that the determining unit determines that thenumber of image formation pages counted by the counting unit havereached the second threshold value, the control unit effects automaticadjustment by the automatic adjustment unit before starting executing ofthe next image formation job even though the number of image formationpages counted by the counting unit has not reached the first thresholdvalue.

According to a third aspect of the present invention, an image formationapparatus for forming images based on input image data comprises: anautomatic adjustment unit for performing automatic adjustment of theimage formation apparatus; a counting unit for counting the number ofimage formation pages from the previous automatic adjustment, for eachautomatic adjustment item which the automatic adjustment unit performs;a control unit for effecting automatic adjustment by an automaticadjustment unit, in response to the number of image formation pagescounted by the counting unit reaching a first threshold value; a settingunit for setting a second threshold value smaller than the firstthreshold value; and a determining unit for determining, at the time ofan interruption of an image formation job, whether or not the number ofimage formation pages counted by the counting unit have reached thesecond threshold value set by the setting unit; wherein, in the eventthat the determining unit determines that the number of image formationpages counted by the counting unit have reached the second thresholdvalue, the control unit effects automatic adjustment by the automaticadjustment unit before resuming from the interruption of the imageformation job even though the number of image formation pages counted bythe counting unit has not reached the first threshold value.

According to a fourth aspect of the present invention, an imageformation apparatus for forming images based on input image datacomprises: an acquiring unit for acquiring indicators relating to thetime for performing the next maintenance for predetermined maintenanceitems; and a display unit for displaying indicators acquired by theacquiring unit for each maintenance item, along with the amount of timerequired for the maintenance.

According to a fifth aspect of the present invention, an image formationapparatus for forming images based on input image data comprises: anacquiring unit for acquiring indicators relating to the time forperforming the next maintenance for predetermined maintenance items; anda display unit for displaying indicators acquired by the acquiring unitfor each maintenance item; wherein the acquiring unit comprises acounting unit for counting the number of image formation sheets from thepoint that the previous maintenance ended for each maintenance item, anda calculating unit for calculating the number of remaining imageformation sheets to the next maintenance, based on the counted number ofimage formation sheets, whereby the calculated number of remaining imageformation sheets is acquired as the indicator.

According to a sixth aspect of the present invention, an image formationapparatus for forming images based on input image data comprises: anacquiring unit for acquiring indicators relating to the time forperforming the next maintenance for predetermined maintenance items; adisplay unit for displaying indicators acquired by the acquiring unitfor each maintenance item; a selecting unit for selecting themaintenance items based on the indicators displayed for each of themaintenance items; and a control unit for controlling the start ofmaintenance corresponding to a selected maintenance item.

According to a seventh aspect of the present invention, an imageformation apparatus for forming images based on input image datacomprises: an acquiring unit for acquiring indicators relating to thetime for performing the next maintenance for predetermined maintenanceitems; a display unit for displaying indicators acquired by theacquiring unit for each maintenance item; a transmission unit fortransmitting indicators acquired for each of the maintenance items toother apparatuses; a reception unit for receiving maintenance itemsselected by the other apparatuses based on the transmitted indicators;and a control unit for controlling the start of maintenancecorresponding to the received maintenance items.

Due to the above configurations, the downtime due to adjustment can bereduced at the time of performing jobs. That is to say, the user caneasily confirm the adjustment item which could be performed during thenext job, in idle time up to the next job, at the time of turning on thepower supply, or the like. Also, in the event that there is time up tothe next job, the user can perform adjustment beforehand. Further, theuser can select multiple adjustment items, and accordingly, the selectedmultiple adjustment items can be performed at the same time, therebymarkedly reducing the downtime due to adjustment during the job.

Furthermore, multiple image formation apparatuses are connected througha network, and accordingly, the user can easily confirm the adjustmentitem of any image formation apparatus, which could be performed duringthe next job, from another image formation apparatus, and moreover, theuser can give adjustment instructions for the image formation apparatusfrom the another one. thus, the user can give adjustment instructionsfor any image formation apparatus connected to the network from anotherimage formation apparatus, so even in the event that the image formationapparatuses are situated distant one from another, the user can performadjustment without the user moving to the distant image formationapparatus.

Further objects, features and advantages of the present invention willbecome apparent from the following description of the preferredembodiments (with reference to the attached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram which illustrates a configuration of an imageformation apparatus according to a first embodiment.

FIG. 2 is a block diagram which illustrates a configuration of an imageprocessing unit 312.

FIG. 3 is a diagram which illustrates a configuration of an LED imagerecording unit.

FIG. 4 is a diagram which illustrates a electronic configuration of aprinter unit 300.

FIG. 5 is a diagram which illustrates a configuration of a densitysensor.

FIG. 6 is a diagram for describing the density sensor 971 detecting thedensity of a patch P formed on a density belt 333.

FIG. 7 is a diagram which illustrates a configuration of a registrationsensor.

FIG. 8 is a diagram which illustrates a configuration of a finisher 400.

FIG. 9 is a diagram which illustrates an external view of an operationdisplay unit 550.

FIG. 10 is a flowchart which shows steps for execution processing forthe adjustment mode.

FIG. 11 shows a table which indicates queuing of jobs.

FIG. 12 shows a table which indicates a threshold value X, a presentcount Y, a remaining number of pages, and the like, for each adjustmentitem.

FIG. 13 is a flowchart which shows steps for execution processing forthe adjustment mode according to a second embodiment.

FIG. 14 shows a table which indicates a threshold value X, a secondthreshold value X2, and a present count value Y, for each adjustmentitem.

FIG. 15 is a flowchart which shows steps for execution processing forthe adjustment mode according to a third embodiment.

FIG. 16 is a flowchart which shows steps for update processing for thesecond threshold value according to a fourth embodiment.

FIG. 17 is a circuit diagram which illustrates a configuration of avideo signal count unit 220.

FIG. 18 shows a table which indicates the second threshold values.

FIG. 19 is a diagram which illustrates a configuration of an imageformation system according to an embodiment.

FIG. 20 is a diagram which illustrates a configuration of another imageformation system.

FIG. 21 is a diagram which illustrates an external view of the operationdisplay unit 550.

FIG. 22 is a diagram which illustrates a maintenance management screendisplayed on the operation display unit 550.

FIG. 23 is a diagram which illustrates an adjustment screen displayed onthe operation display unit 550.

FIG. 24 is a diagram which illustrates a threshold change screendisplayed on the operation display unit 550.

FIG. 25 is a diagram which illustrates a status screen displayed on theoperation display unit 550.

FIG. 26 is a diagram which illustrates a list screen for expendablesdisplayed on the operation display unit 550.

FIG. 27 is a flowchart which shows steps for adjustment executionprocessing performed at the time of the user selecting a maintenance key563 on the operation display unit 550 of the image formation apparatus.

FIG. 28 is a diagram which illustrates a configuration of a network.

FIG. 29 is a diagram which shows the flow of data on the network.

FIG. 30 is a diagram which illustrates a screen of a printer driver.

FIG. 31 is a diagram which illustrates a main screen of a web serviceprovided within a document server 1102.

FIG. 32 is a diagram which illustrates a device display portion 1707.

FIG. 33 is a diagram which illustrates a job status display portion1709.

FIG. 34 is a diagram which illustrates a job history display portion1711.

FIG. 35 is a diagram which illustrates a device status tab 1702.

FIG. 36 is a flowchart which shows steps for adjustment executionprocessing at the time of performing adjustment mode followinginstructions from another image formation apparatus connected to thenetwork.

FIG. 37 is a diagram which shows an item list for maintenance.

FIG. 38 is a diagram which shows an item list for maintenance.

FIG. 39 is a diagram which shows an item list for maintenance.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

FIG. 1 is a diagram which illustrates a configuration of an imageformation apparatus according to a first embodiment. The image formationapparatus principally comprises a color reader unit 200, a printer unit300, and a finisher unit 400.

[Color Reader Unit]

First, description will be made regarding the configuration of the colorreader unit 200. Reference numeral 101 denotes a CCD, 311 denotes aboard where the CCD 101 has been mounted, and 312 denotes an imageprocessing unit. The image processing unit includes a circuit (notincluding the CCD 101) shown in FIG. 2, a binary conversion unit 201shown in FIG. 3, video signal count units 220 through 223, and delayunits 202 through 205.

Reference numeral 301 denotes a document table glass (platen), and 302denotes a document feeder (DF). Note that instead of employing thedocument feeder 302, the image formation apparatus may have aconfiguration including a flat pressing plate. Reference numerals 303and 304 denote light sources (halogen lamp or fluorescent lamp) forilluminating a document sheet. Reference numerals 305 and 306 denotecurved reflectors for collecting the light from the light sources 303and 304 to the document.

Reference numerals 307 through 309 denote mirrors, and 310 denotes alens for collecting the reflected light or projected light from thedocument sheet onto the CCD 101. Reference numeral 314 denotes acarriage for storing the halogen lamps 303 and 304, curved reflectors305 and 306, and a mirror 307. Reference numeral 315 denotes a carriagefor storing mirrors 308 and 309. Reference numeral 313 denotes aninterface for communicating with other IPUs (image processing units) orthe like.

Note that the carriage 314 is automatically moved with a speed V, andthe carriage 315 is automatically moved with a speed V/2 in thedirection orthogonal to the electrical scanning (main scanning) of theCCD 101, i.e., auxiliary scanning is performed, whereby the entire faceof the document sheet is scanned.

[Image Processing Unit]

FIG. 2 is a block diagram which illustrates a configuration of the imageprocessing unit 312. The light from the light sources 303 and 304 isreflected by the document sheet on the document table glass 301, and thereflected light is introduced onto the CCD 101 so as to be converted toelectric signals. With the CCD 101 comprising color sensors, anarrangement may be made wherein RGB color filters are disposed inline ona single-line CCD in the order of R, G, and B, an arrangement may bemade wherein the CCD 101 comprises a three-line CCD with an R-filter, aG-filter, and a B-filter arrayed on each line of the CCD, an arrangementmay be made wherein an on-chip filter is employed, or an arrangement mayhave a separate configuration for the filters and the CCD.

Upon electric signals (analog image signals) being input to the imageprocessing unit 312 from the CCD 101, the electric signals are held as asample by a first processing unit 102 (clamp, amplification, S/H, A/D),the dark level of the analog image signal is clamped to the standardpotential, is amplified with a predetermined gain, and is subjected toA/D conversion. In A/D conversion, the analog signals are converted into8-bit signals for each of R, G, and B.

A shading unit 103 performs shading correction and black correction forthe RGB signals, following which the corrected signals are input to asecond processing unit 104 (sampling time correction, MTF correction,document detection). First, description will be made regardingsampling-timing correction. In a case that the CCD 101 is a three-lineCCD, the reading positions are different between the three CCD lines atthe same sampling time, and accordingly, the delay time is calculatedfor each CCD line based upon reading speed, and sampling timing iscorrected using the calculated delay time so that the reading positionsof the three CCD lines become the same. With the MTF correction, thechange in MTF due to the change in the reading speed or magnification iscorrected. With the document detection, the size of the document sheetis detected by scanning the document sheet on the document table glass.

Upon the digital signals subjected to the above-describedsampling-timing correction being input to an input masking unit 105, theinput masking unit 105 performs correction with regard to the spectralsensitivity of the CCD 101, and the spectral properties of the lightsources 303 and 304, and the curved reflectors 305 and 306. The inputmasking unit 105 outputs the corrected signals to a selector 106 forperforming switching between the corrected signals and external signalsthrough interfaces. The signals output from the selector 106 are inputto a third processing unit 107 (color space compression, removal ofbackground, log conversion) and a background removal unit 115.

The signals input to the background removal unit 115 are subjected toremoval of the background, following which the signals are input to ablack-character determination unit 116 for determining whether or notthere are any black characters in the document, and the black-characterdetermination unit 116 generates black-character signals from thedocument. As described above, the same output signals from the selector106 are input to the third processing unit 107 for performingcolor-space compression. With the aforementioned color-spacecompression, first, determination is made whether or not the imagesignals read out are in the range which can be reproduced by theprinter. Subsequently, in the event that the image signals are in therange, the image signals pass through this processing without change,otherwise, the image signals are corrected so that the image signals arein the range. Furthermore, the third processing unit 107 performsbackground removal processing, and logarithm conversion for convertingthe RGB signals into the CMY signals. The signals output from the thirdprocessing unit 107 is subjected to timing adjustment by the delay unit108 so as to match the timing of the signals generated by theblack-character determination unit 116.

The aforementioned two kinds of signals are subjected to removal ofmoiré by a moiré removal unit 109, and are subjected to magnificationprocessing in the main-scanning direction by a magnification processingunit 110. Upon the signals subjected to the aforementioned processing bythe magnification processing unit being input to a fourth processingunit 111 (UCR, masking, adjustment of black characters), the fourthprocessing unit 111 performs UCR processing wherein CMYK signals aregenerated from the CMY signals, performs masking processing wherein thegenerated CMYK signals are corrected into signals suitable for printout,and adjusts the CMYK signals based upon the determination signalsgenerated by the black-character determination unit 116.

The signals subjected to the above-described processing by the fourthprocessing unit 111 are subjected to density adjustment by a γcorrection unit 112, following which the signals are subjected tosmoothing or edge processing by a filter unit 113. The signals subjectedto such processing are converted from eight-bit signals of into one-bitsignals by the binary conversion unit 201. Binary conversion may be madewith any of the dithering-method, the error-diffusion method, theimproved error-diffusion method, and the like.

[Printer Unit]

Next, description will be made regarding a configuration of the printerunit 300. In FIG. 1, reference numeral 317 denotes a yellow imageformation unit, 318 denotes a magenta image formation unit, 319 denotesa cyan image formation unit, and 320 denotes a black image formationunit. These image formation units have the same configuration, sodescription will be made regarding the yellow image formation unit 317in detail, and description of other image formation units will beomitted.

With the yellow image formation unit 317, reference numeral 342 denotesa photosensitive drum for forming a latent image thereon due to thelight from an LED array 210. Reference numeral 321 denotes a primarycharger for charging the surface of the photosensitive drum 342 to apredetermined potential for preparing formation of latent images.Reference numeral 322 denotes a developing device for forming tonerimages by developing the latent images on the photosensitive drum 342.Note that the developing device 322 includes a sleeve 345 for applying adeveloping bias for developing. Reference numeral 323 denotes a transfercharger for performing discharge from the back of a transfer belt 333 soas to transfer the toner images on the photosensitive drum 342 onto arecording sheet or the like mounted on the transfer belt 333.

Next, description will be made regarding a process for forming images ona recording sheet or the like. The recording sheets stored in thecassettes 340 and 341 are supplied one by one by a pickup rollers 338and 339, and are supplied onto the transfer belt 333 by feeding rollers336 and 337. The supplied recording sheet is charged by a pickup charger366. Reference numeral 368 denotes a transfer belt roller for drivingthe transfer belt 333, and makes up a pair along with the pickup charger366 so as to charge the recording sheet or the like, whereby therecording sheet or the like is picked up onto the transfer belt 333.Reference numeral 367 denotes a leading-edge detector for detecting theleading edge of the recording sheet or the like on the transfer belt333. Note that the detected signal from the leading-edge detector istransmitted to the color reader unit 200 from the printer unit 300 forusing as an auxiliary scanning synchronous signal at the time oftransmitting video signals from the color reader unit 200 to the printerunit 300.

Subsequently, the recording sheet or the like is transported by thetransfer belt 333, and toner images are formed thereon by the imageformation units 317 through 320 in the order of yellow (Y), magenta (M),cyan (C), and black (K). The recording sheet or the like output from theblack image formation unit 320 is subjected to removal of charge by acharge-removal unit 349 in order to facilitate separation from thetransfer belt 333, following which the recording sheet or the like isseparated from the transfer belt 333. Reference numeral 350 denotes aseparation charger for preventing deterioration of images due toseparation discharge at the time of the recording sheet or the likeseparating from the transfer belt 333. The separated recording sheet orthe like is charged by pre-fixing chargers 351 and 352 in order toprevent deterioration of images by assisting adsorption of the toner,following which a fixing device 334 performs thermal fixing for thetoner images. Subsequently, the recording sheet or the like istransported to the finisher unit 400.

[Led Image Recording]

FIG. 3 is a diagram which illustrates a configuration of an LED imagerecording unit. As described above, the binary conversion unit 201, thevideo signal count units 220 through 223, and the delay unit 202 through205 are included in the image processing unit 312. LED driving units 206through 209 and LED units 210 through 213 are included in the imageformation units of the yellow, magenta, cyan, and black, respectively.

The signals of Y, M, C, and K from the image processing unit 312 shownin FIG. 2 are converted into one-bit signals by the binary conversionunit 201, and are transmitted to the video signal count units 220through 223 which are image information detecting means. The videosignal count units 220 through 223 can count the total number ofemission times of the LEDs for each color image.

Subsequently, the image signals subjected to binary processing aredelayed by the delay units 202 through 205 corresponding to the distancebetween the leading-edge detector 367 and each of image formationpositions, and are transmitted to the LED driving units 206 through 209.The LED driving units 206 through 209 generate signals for driving theLED units 210 through 213, respectively.

[Electric Configuration of the Printer Unit]

FIG. 4 is a diagram which illustrates an electric configuration of theprinter unit 300. The printer unit 300 includes a CPU 15, ROM 11, RAM12, EEPROM 13, a developing bias generating unit 14, a registrationsensor 972, a density sensor 971, and the like. Furthermore, the CPU 15is connected to an operating display unit 550 described later.

The ROM 11 stores programs and the like for being performed by the CPU15. The RAM 12 temporarily stores control data for controlling theprinter unit, calculated results from the CPU 15, and the like. TheEEPROM (non-volatile memory) 13 stores for each adjustment item thenumbers of copies (X1, X2, and so forth) from the preceding adjustmentsuch as density adjustment, registration adjustment, and the like, up tothe next adjustment as threshold values, and the numbers of copies (Y1,Y2, and so forth) from the preceding adjustment up to the present time.Furthermore, the EEPROM 13 stores adjustment values for the developingbias in the density adjustment, adjustment values for various sensors,and the like.

[Density Adjustment Processing]

Next, description will be made regarding density adjustment processingwhich is one of the adjustment modes (automatic adjustment ormaintenance) described later. This processing is performed by the CPU 15within the printer unit 300. In general, electrophotographic color imageformation apparatuses have a problem in that, in the event thatdeviation of the image density occurs due to the change in theenvironment where the image formation apparatus is situated, the numberof copies, or the like, copies cannot be made in normal color tone. Withthe present embodiment, density-detecting toner images (patches) P areformed on the transfer belt 333 for each color toner as test patterns(see FIG. 6), the density of each patch is detected by the densitysensor 971, and image density control is performed by performingadjustment based upon the detected results.

FIG. 5 is a diagram which illustrates a configuration of the densitysensor. The density sensor 971 comprises a light-emission device 2 asuch as an LED, a light-receiving device 2 b such as a photodiode, and aholder 2 c. The infrared light from the light-emission device 2 a isilluminated onto the patch P on the transfer belt 333, and the reflectedlight from the patch P is measured by the light-receiving device 2 b,whereby the density of the patch P is measured.

Note that the reflected light from the patch P includes theregular-reflection component and the diffused-reflection component. Withthe present invention, either a method for detecting theregular-reflection component or a method for detecting thediffused-reflection component may be employed. However, the method fordetecting the regular-reflection component (see FIG. 7) has a problem inthat the amount of light greatly changes due to the state of the surfaceof the transfer belt 333 which is a background of the patch, or thechange in the distance between the density sensor 971 and the patch P,leading to difficulty in maintaining precision of detection.Accordingly, with the present embodiment, the method for detectingdiffused reflected light is employed. Accordingly, as shown in FIG. 5,taking the normal I as a reference line, the density sensor 971 performsmeasurement with the illumination angle α onto the patch P of 45°, andthe receiving angle β from the patch P of 0° so as to eliminate theregular reflected light from the light cast to the light-receivingdevice 2 b, and so as to measure only the diffused reflected light.

FIG. 6 is a diagram for describing the density sensor 971 detecting thedensity of the patch P formed on the transfer belt 333. With the actualdensity detecting method for the patch P, a square pattern with thewidth of 14 mm and the height of 14 mm is employed as a pattern of thepatch P. The patch pattern is a half-tone pattern subjected to apredetermined dithering processing. Taking the pattern formed by fullexposure as 100%, the pattern employed in the present embodimentcorresponds to around 60%.

Developing is performed with the developing bias generated by thedeveloping generating unit 14 being changed for each predeterminedspacing so as to form multiple patch patterns, and the density of eachpatch pattern is detected by the density sensor 971. The developing biasfor forming a patch pattern with a predetermined density is calculatedbased upon the detected values. The bias value is calculated for eachcolor, and the calculated developing bias values are used at the time ofimage formation. Such control is referred to as “developing biascontrol”.

Furthermore, an arrangement may be made wherein developing is performedwith a calculated and fixed developing bias value for a half-tonepattern subjected to a predetermined dithering processing with the tone(exposure amount) changed for each constant spacing so as to formmultiple patch patterns, and the density of each patch pattern isdetected by the density sensor 971. Furthermore, an arrangement may bemade wherein the exposure amount is corrected at the time of ditheringprocessing so as to obtain smooth tone based upon the detected values.The control is referred to as “half-tone control”.

Note that the density of the patch pattern is calculated fromsubtraction of the signal values of the reflected light from only thebackground of the electrostatic transporting belt measured prior todensity control from the signal values of the reflected light from thepatch pattern formed on the belt.

The image density control is preferably performed at the time of turningthe power supply on, at the time of replacement of expendables such ascartridges or the like, at the time of the number of copies reaching apredetermined number after performing the preceding image densitycontrol, or the like. Furthermore, the image density control may beperformed following adjustment instructions from the operation displayunit 550 described later at a timing specified by the user. Furthermore,the image density control may be performed at a timing performedaccording to a flowchart described later.

[Registration Adjustment Processing]

Next, description will be made regarding to the registration adjustmentprocessing which is one of the adjustment modes (automatic adjustment ormaintenance) described later. The image formation apparatus includes theregistration sensor 972 (see FIG. 7) at the portion facing the transferbelt 333 within the main unit thereof. The tandem color image formationapparatus according to the present embodiment transfers toners in fourcolors onto the transfer member for each color, and mixes these colortoners at the time of fixing so as to reproduce color images. That is tosay, in the event that the colors are not overlaid in a precise mannerat the time of transferring the toners onto the transfer member, colorimages cannot be obtained with the normal color tone.

Accordingly, with the present embodiment, registration detecting tonerimages (lines) are formed on the transfer belt 333 for each color toneras test patterns, the transfer position is detected by the registrationsensor 972 for each color, and the start timing of formation of theelectrostatic latent image by the laser scanning and exposure isadjusted based upon the detected results. The above-described processingis referred to as “registration control”.

The same optical density sensor as with the density sensor 971 can beemployed as the registration sensor 972. Note that with the registrationcontrol, the transfer position is detected from the change in the amountof the received light at the time of the line passing through the fieldof view of the registration sensor 972, and the start timing offormation of the electrostatic latent image is corrected with regard totime based thereupon.

Note that the image density control is performed in order to detect thedifference in the density between the patches, and accordingly, themethod of detecting the diffused reflection component is employed forobtaining stable detection of the reflected light. However, theregistration control is performed in order to detect the change in theabsolute value of the light amount at the time of the line passingthrough the field of view of the registration sensor, the registrationsensor employing the regular-reflected-light detecting method, shown inFIG. 7, using the regular reflected light which has a great absolutevalue, is employed. FIG. 7 is a diagram which illustrates aconfiguration of the registration sensor.

That is to say, taking the normal I as a reference line, theregistration sensor 972 performs measurement with the illumination angleα onto the patch P of 45°, and the receiving angle β from the patch P of45°. As a result, the registration sensor 972 measures both the diffusedreflected light and the regular reflected light, but the regularreflection component is incomparably greater than the diffusedreflection component, and accordingly, contribution of the diffusedreflection component is negligible. Note that either of thereflected-light detecting methods may be employed for the densitydetection and the registration detection. Accordingly, an arrangementmay be made wherein both the density detection and the registrationdetection are performed using only one optical density sensor employingeither the regular-reflected-light detecting method or thediffused-reflected-light detecting method for reducing costs.

The registration control is preferably performed at the time of thepower supply being turned on, at the time of replacement of expendablessuch as a cartridge, electrostatic transporting belt, or the like, atthe time of the number of copies reaching a predetermined number afterperforming the preceding registration control, or the like. Furthermore,the registration control may be performed at a timing specified by theuser according to adjustment instructions from the operating displayunit 550 described later.

[Configuration of the Finisher Unit 400]

FIG. 8 is a diagram which illustrates a configuration of the finisherunit 400. The sheet output from the fixing unit 334 of the printer unit300 is transported to the finisher unit 400. The finisher unit 400includes a sample tray 1101 and a stack tray 1102, for switching to asuitable tray according to the type of the job or the number of sheetwhich are to be discharged.

Two types of sort methods are known. One is the bin sort method whereinoutput sheets are distributed to multiple bins. The other is the shiftsort method wherein output sheets are distributed for each job using theelectronic sort function with the bin or the tray being shifted inwards.Thus, sorting can be realized. The electronic sort function is alsoreferred to as a “collating function”, wherein the document stored inlarge-size buffer memory included in the core unit is output in adesired page number order, so as to support sorting.

The group function is a function for distributing output sheets for eachpage, while sorting is a function for distributing output sheets foreach job. Furthermore, an arrangement may be made wherein the outputsheets which are to be discharged to the stack tray 1102 are stored foreach job, and the stored sheets are bound by a stapler 1105 for each jobimmediately prior to discharging.

Furthermore, the finisher unit 400 includes a Z-folding device 1104 forfolding a paper sheet in the shape of the letter Z, and a puncher 1106for punching two or three holes for filing, on a path up to theaforementioned two trays. Each processing is performed according to thetype of the job.

Furthermore, a saddle stitcher 1107 binds the output sheets at twoportions on the center thereof, following which the sheets are nipped bythe roller at the center portion thereof so as to form a booklet infolio such as a magazine, pamphlet, or the like. The booklet formed ofthe sheets bound by the saddle stitcher 1107 is discharged onto abooklet tray 1108. Furthermore, an arrangement may be made whereingluing is performed for binding the sheets into a booklet, or anarrangement may be made wherein trim is performed so as to true up theend face opposite to the binding side after binding (both not shown).

An inserter 1103 transports sheets set on a tray 1110 to any of thetrays 1101, 1102, and 1108, without passing through the printer. Thus,the sheet set to the inserter 1103 can be inserted between the sheetswhich are to be transported to the finisher unit 210.

Upon the user setting the sheets face up on the tray 1110 of theinserter 1103, the sheets are supplied by a pickup roller 1111 in orderfrom the topmost sheet. The sheets are transported directly from theinserter 1103 to the tray 1101 or tray 1102, and are discharged facedown. In the event of transporting the saddle stitcher 1107, the sheetsare temporarily transported to the puncher 1106, following which thesheets are transported to the saddle stitcher 1107 so as to match theface direction of the sheets.

[Operating Display Unit]

FIG. 9 is a diagram which illustrates an external view of the operatingdisplay unit 550. The operating display unit 550 includes various kindsof key groups and a LCD (liquid crystal display) 551. The LCD 501 isformed of a touch panel of which the surface is transparent. Variouskinds of messages can be displayed on the LCD 501, and furthermore,various kinds of input keys are displayed so that the user can inputcommands by pressing the input keys displayed thereon.

Of the input key groups, reference numeral 552 denotes a numericalkeypad for inputting values such as the number of copies. Referencenumeral 553 denotes a copy start key for starting copy. Referencenumeral 554 denotes a stop key for stopping copy operations.

Reference numeral 555 denotes a copy density key for adjusting the copydensity manually. Reference numeral 556 denotes an AE key for switchingto the automatic mode wherein the copy density is automatically adjustedaccording to the density of the document, or canceling AE (automaticdensity adjustment) and switching to the manual mode wherein the copydensity is manually adjusted.

Reference numeral 557 is a copy mode key for entering the copy mode.Note that the image formation apparatus includes the copy queuingfunction wherein upon the user setting the following document onto thedocument feeder (DF) 302 following the preceding document being readout, the document can be read out and queued as a next copy job, evenduring printout for the previous job. Reference numeral 559 denotes afax mode key for performing the fax function.

Reference numeral 558 denotes a cassette selection key (sheet selectionkey) for selecting the upper cassette 341 or the lower cassette 340. Inthe event that the document is placed on the document feeder (DF) 302,the user can select APS (automatic paper selection) with the cassetteselection key 558. In the event that APS is selected, the imageformation apparatus automatically selects a cassette storing sheets ofthe same size as the document. Reference character 562 denotes a usermode key for the user changing the settings of the present imageformation apparatus. The settings which can be changed by the userinclude how long the input settings are to be held from the time of thesetting being input (the input settings are automatically cleared afterthis period), default settings of the mode at the time of the reset keybeing pressed, and the like, for example.

Reference numeral 562 denotes a key for selecting an operation mode forthe finisher 400. Upon the user pressing the key 562, the LCD 551displays the screen for selecting the staple mode, folding mode, or thelike. Reference numeral 561 denotes an advanced mode key for performingsettings of the advanced modes such as settings of the binding margin,photographic mode, multiple processing, dual page copying, 2 in 1 mode,and so forth.

[Adjustment Processing]

FIG. 10 is a flowchart which illustrates the processing steps executedfor an adjustment mode. The processing program is stored in the ROM 11within the printer unit, and is executed by the CPU 15. First,determination is made whether or not the job has ended (Step S101). Inthe event that the job has not ended, the processing in Step S101 isrepeated. In the event that the job has ended, determination is madewhether or not there are any subsequent jobs queued (Step S102). In theevent that there are no subsequent jobs queued, the present processingends.

On the other hand, in the event that there is a subsequent job queued,the image formation apparatus checks the details of the next job (StepS103). FIG. 11 shows a table indicating the queuing of the jobs. Here,the job 1 is running at the present time, job 2 is for printing 100pages×2 copies, and job 3 is for printing 10 pages×50 copies. The numberof total printing pages is confirmed in the analysis of the details ofthe next job.

Subsequently, determination is made whether or not the image formationapparatus has any adjustment items for the adjustment mode executedduring the next job (Step S104). The determination is made as follows.With the threshold value for determining the time of next adjustmentfrom the time of the preceding adjustment as X, and with the number oftotal copies from the time of the preceding adjustment up to the presenttime as Y (present count), the number of the remaining copies, which canbe performed up to the next adjustment, is represented by X−Y. Note thatthe parameters such as the aforementioned threshold value X, presentcount Y, and the like, are stored in the EEPROM 13. With the number oftotal copies for the next job as Z, in the event that the relationrepresented by Expression (1) holds, the image formation apparatusdetermines that the total number of copies reaches the threshold forexecuting the adjustment mode during the next job.Z>X−Y  (1)

FIG. 12 shows a table indicating the threshold values X, present countY, remaining number of pages, and the like, for each adjustment item. Asspecific examples of the adjustment items, the density adjustment andthe registration adjustment are shown in the table, but each imageformation apparatus has particular adjustment items, and accordingly, itis needless to say that the adjustment items are not restricted to theexamples.

In this table, the threshold values X are set to 500 pages for bothadjustment modes. These threshold values are set to particular valuesfor each image formation apparatus, but the user can change thethreshold values with the operation display unit 550. In addition, thenumber of pages printed (present count) Y from the time of the precedingadjustment up to the present time are 450 pages and 200 pages for thedensity adjustment and the registration adjustment, respectively.Accordingly, the remaining number of pages (X−Y) wherein copies can beperformed up to the next adjustment are 50 pages and 300 pages,respectively. Furthermore, the number of the total copies Z for the nextjob is 200 pages corresponding to the job 2 of the queued jobs shown inFIG. 11. Accordingly, the image formation apparatus determines whetheror not the number of pages printed will reach the threshold forperforming the adjustment mode during the next job by makingdetermination whether or not the relation of Expression (1) holds. Here,the above-described relation holds with regard to the item of thedensity adjustment, and accordingly, the image formation apparatusdetermines that the number of pages printed will reach the threshold forexecuting the density adjustment during the next job. On the other hand,the above-described relation does not hold with regard to the item ofthe registration adjustment, and accordingly, the image formationapparatus determines that the number of pages printed will not reach thethreshold for executing the adjustment mode during the next job.

In Step S104, in the event that determination is made that there are noadjustment mode items to be executed during the next job, the presentprocessing ends. On the other hand, in the event that determination ismade that the image formation apparatus has an item for the adjustmentmode executed during the next job, the corresponding adjustment mode isexecuted (Step S105). As described above, here, the density adjustmentmode is executed. Subsequently, determination is made whether or not theadjustment mode has ended (Step S106). In the event that determinationis made that the adjustment mode has not ended, the processing in StepS106 is repeated. On the other hand, in the event that determination ismade that the adjustment mode has ended, the corresponding present countY (in this case, the count value for the density adjustment) is cleared(Step S107). Subsequently, the present processing ends.

In general, there is some time between the individual jobs foroperations performed by the user, such as picking up the dischargedsheets from the stack tray or the booklet tray of the finisher 400,supplying sheets for the next job, or the like. With the presentembodiment, the adjustment mode of the adjustment item, whereindetermination is made that the number of printed pages reaches thethreshold for executing the adjustment mode during the next job, isexecuted between the individual jobs beforehand, thereby reducing thedowntime during the job, and reducing the number of times of adjustment.Furthermore, adjustment is not executed during the job, therebypreventing difference in image quality between the copies before andafter the execution of the adjustment mode within a single job.Furthermore, with the present embodiment, the adjustment mode isexecuted between the individual jobs, and accordingly, the adjustmentmode is executed around the threshold for executing the adjustment mode,thereby obtaining excellent image quality.

Second Embodiment

FIG. 13 is a flowchart showing the processing steps executed for theadjustment mode according to a second embodiment. The processing programthereof is stored in the ROM 11 within the printer unit, and is executedby the CPU 15. First, determination is made whether or not the job hasended (Step S201). In the event that determination is made that the jobhas ended, the processing in Step S201 is repeated, otherwisedetermination is made whether or not the present count Y for eachadjustment item is greater than the second threshold value X2 (Y>X2)(Step S202).

Note that the second threshold value X2 can be input by the user withthe operation display unit 550, and is set to a value smaller than thethreshold value (X) by a predetermined value. FIG. 14 shows a tableindicating the threshold values (X), the second threshold values X2, andthe present count values Y, for each adjustment item. In an example ofthe present embodiment, the second threshold values X2 is smaller thanthe threshold value X by 50 pages, respectively. Note that anarrangement may be made wherein the second threshold value X2 isautomatically updated according to the details of the job in apredetermined period.

In Step S202, in the event that determination has been made that all thepresent count values Y of the adjustment items are equal to or less thanthe second threshold values X2, respectively, the present processingends. In this example, only the present count Y of the registrationadjustment is less than the second threshold value X2 (Y<X2), and thepresent count Y of the density adjustment is greater than the secondthreshold value X2 (Y>X2).

In Step S202, in the event that determination is made that at least oneof the present count values Y of the adjustment items is greater thanthe second threshold value X2, the corresponding adjustment mode (inthis case, the density adjustment mode) is executed (Step S203). Notethat in the event that the image formation apparatus has multiplerequired adjustment modes, the multiple adjustment modes areconsecutively executed. Subsequently, the image formation apparatuswaits for the processing to end (Step S204). In the event that theexecution of the adjustment mode has ended, the present count Y iscleared in Step S205, and the present processing ends.

As described above, with the present embodiment, the user can set andchange the second threshold values, and accordingly, the adjustmentitems for the adjustment modes which might be executed during the nextjob depending upon the density of a printout such as a characterprintout, solid picture printout, or the like, are found beforehand, andare executed before starting the job. Thus, the downtime during the jobis reduced, and the number of times of adjustment is reduced.

Third Embodiment

FIG. 15 is a flowchart which shows the processing steps executed for theadjustment mode according to a third embodiment. The processing programthereof is stored in the ROM 11 within the printer unit, and is executedby the CPU 15. First, determination is made whether or not the job hasbeen interrupted (Step S301). Here, interruption of the job means thatthe job has been interrupted to supply sheets, supply staples for thefinisher, pick up the output sheets following detection of the stacktray being full, or the like, during the job.

In the event that determination is made that the job has not beeninterrupted, the processing in Step S301 is repeated. On the other hand,in the event that determination is made that the job has beeninterrupted, determination is made whether or not at least one of thepresent count values Y of the adjustment items is greater than thesecond adjustment value X2 (Step S302). Detailed description regardingthe second threshold values X2 and the step processing has been made inthe above second embodiment, so description thereof will be omitted.

In the event that all the present count values Y of the adjustment itemsare equal to or less than the second threshold values X2, respectively,the present processing ends. On the other hand, in the event that atleast one of the present count values Y of the adjustment items isgreater than the second threshold value X2, the corresponding adjustmentmode is executed (Step S303). In FIG. 14, the item of the densityadjustment matches the criteria, and accordingly the density adjustmentmode is executed. Note that in the event that there are multiplerequired adjustment modes, the other required adjustment modes areconsecutively executed.

Subsequently, determination is made whether or not the adjustment modehas ended (Step S304). In the event that the adjustment mode has notended, the processing in Step S304 is repeated, otherwise the presentcount Y is cleared (Step S305). Subsequently, the processing ends.

With the present embodiment, any adjustment item of an adjustment modewhich might be executed during the job can be found even during the job,and the required adjustment mode is executed during an interruption ofthe job, and accordingly, the brief periods during interruption of jobscan be efficiently used, thereby reducing the downtime during the job,and reducing the number of times of adjustment.

Fourth Embodiment

Description has been made regarding the second threshold values X2 whichhave been set by the user with the operation display unit 550 in theabove second and third embodiments. With a fourth embodiment, the imageformation apparatus determines the threshold values based upon thedetails of the jobs in a predetermined period, and the threshold valuesare automatically updated.

FIG. 16 is a flowchart which shows the steps for updating the secondthreshold values according to the fourth embodiment. The processingprogram thereof is stored in the ROM 11 within the printer unit, and isexecuted by the CPU 15. First, determination is made whether or not thejob count value has reached a predetermined value (Step S401). In anexample of the present embodiment, the aforementioned predeterminedvalue is set to ten, and accordingly, the second threshold values X2 areupdated every 10 jobs.

In the event that the job-count value has not reached the predeterminedvalue, the processing ends. On the other hand, in the event that thejob-count value has reached the predetermined value, M which is theaverage number of pages printed per job is calculated based upon the jobhistory of previous jobs for a predetermined number of times (StepS402). Subsequently, the second threshold values X2 are calculated usingthe Expression (2), and the parameters X2 stored in the EEPROM 13 areupdated (Step S403). Subsequently, the processing ends.Second threshold value (X2)=Threshold value (X)−M  (2)

Note that while description has been made regarding processing whereinthe second threshold values are updated once every predetermined numberof times of jobs being executed, an arrangement may be made wherein theaverage number of pages printed per job is calculated once everypredetermined time period, e.g., once a week.

With the present embodiment, optimal second threshold values can be setaccording to the recent use of the image formation apparatus, therebypreventing excessive adjustment processing.

Fifth Embodiment

Description has been made regarding the processing wherein the secondthreshold value is determined by calculating the average number of pagesprinted (M) per job based upon the job history for the previous jobs inthe predetermined number of times in the above fourth embodiment. With afifth embodiment, the video count values per job is calculated, and thesecond threshold value is determined based thereupon.

In general, the image density is detected for each image formation in aprint job. With the present embodiment, the image density is representedby the number of total emission times of the LEDs counted by the videosignal count units 220 through 223 for each color image (see FIG. 3).

FIG. 17 is a circuit diagram which shows a configuration of the videosignal count unit 220. Note that the video signal count units 221through 223 have the same configuration, so only the configuration ofthe video signal count unit 220 will be described. The video signalcount unit 220 receives image signals 700 from the binary conversionunit 201, and the image signals of one image are counted as 8-bit databy 29-bit counters 701 through 708 in parallel. Addition of theseresults is made by a 32-bit adder 709, whereby the number of totalemission times of the LEDs is obtained as 32-bit data from the additionresult.

Such processing is performed for each image formation in order to obtainthe number of total emission times of the LEDs (which will be referredto as “video count value hereafter), and addition of the video countvalues is made for the total number of pages over one job, which will bereferred to as “Vsum” hereafter. The addition of the Vsum is made over apredetermined number of job times, and the addition is divided by thetotal number of pages for the predetermined number of job times, wherebythe average video count value per page AVsum is obtained. The greaterthe image density of the printed image is, the greater the AVSum is.Accordingly, with the present embodiment, with the AVsum for a solidimage as Vmax, determination is made whether or not the AVsum is greaterthan (½)*Vmax so as to determine the second threshold.

FIG. 18 shows a table which indicates the second threshold values. Thesecond threshold values are determined using the table shown in FIG. 18.Thus, in the event that the image density of the printed image is closeto that of the complete solid image, the image formation apparatusaccording to the present embodiment increases the frequency ofadjustment.

As described above, the image formation apparatus according to the aboveembodiments has the advantages described below. In general, there issome time between the individual jobs for the operation performed by theuser, such as picking up the discharged sheets from the stack tray orthe booklet tray of the finisher 400, supplying sheets for the next job,or the like. With the above embodiments, the adjustment mode of anadjustment item wherein the determination parameter for executing theadjustment will reach the threshold value during the next job isexecuted between the individual jobs beforehand, thereby reducing thedowntime during the job, and reducing the number of times of adjustment.

Furthermore, the user can set the second threshold value, which issmaller than the first threshold value, for determining adjustmentexecuted between the individual jobs. With the above embodiments, anadjustment mode wherein determination parameter for executing theadjustment could reach the threshold value during the next job isexecuted prior to the job, thereby reducing the downtime during the job,and reducing the number of times of adjustment.

Furthermore, with the above embodiments, the user can set the secondthreshold value which is smaller than the first threshold value, andaccordingly, in the event that the job is interrupted due to supplyingsheets, supplying staples for the finisher, detection of the stack traybeing full, or the like, the adjustment mode wherein determinationparameter for executing the adjustment could reach the threshold valueduring this job is executed during interruption of the job, andaccordingly, the brief periods during interruption of jobs can beefficiently used, thereby reducing the downtime during the job, andreducing the number of times of adjustment.

Furthermore, with the above embodiments, the user can input the secondthreshold values with the operation display unit, and accordingly, theuser can freely set the second threshold according to the details of thejobs which are normally performed, thereby improving ease of use of theimage formation apparatus.

Furthermore, with the above embodiments, the second threshold values areautomatically updated according to the details of the jobs in apredetermined period. Thus, the second threshold values are set tooptimal values corresponding to use of the image formation apparatus,thereby preventing excessive execution of adjustment modes.

While description has been made regarding the embodiments according tothe present invention, the present invention is not restricted to theabove-described embodiments, and the present invention may be applied toany configuration included within scope of the appended claims, or anyconfiguration which can achieve the functions included in theabove-described embodiments.

For example, the second threshold values used in the above-describedsecond and third embodiment may be set to the same value or differentvalues for each adjustment item.

While description has been made in the above-described embodimentsregarding adjustment item as a type of maintenance, and the densityadjustment and the registration adjustment as specific examples, actualmaintenance further includes various types of items. That is to say, themaintenance according to the present invention should be understood inthe broad sense, and encompasses not only adjustment of the component,which means maintenance in the general sense, but also cleaning,replacement and supply of expendables, and the like. Accordingly, theprocessing of each embodiment may be applied to cleaning, replacementand supply of expendables, and the like, as well. Examples of cleaninginclude cleaning of the document table glass, cleaning of thetransporting belt, and the like. Example of replacement of expendablesinclude replacement of a cleaning blade or a charger. Examples of supplyinclude supplying of toner, supply of sheets, and the like.

As described above, with the above-described embodiments, adjustmentmode can be executed at a suitable timing. That is to say, theadjustment mode is executed between the individual jobs, therebyreducing the downtime during the job, and reducing the number of timesof adjustment. Furthermore, with the above-described embodiments, theadjustment mode wherein the determination parameter could reach thethreshold value during the next job is executed prior to the job,thereby reducing the downtime during the job, and reducing the number oftimes of adjustment. Furthermore, brief periods during interruption ofjobs is efficiently used for adjustment, thereby reducing the downtimeduring the job, and reducing the number of times of adjustment.

Sixth Embodiment

[Schematic Configuration of the System]

FIG. 19 is a diagram which illustrates a configuration of an imageformation system according to a sixth embodiment. FIG. 20 is a diagramwhich illustrates a configuration of an image formation system having adifferent network configuration from that in FIG. 19. These imageformation systems have generally the same configuration including adocument server 1202, computers 1203 a, 1203 b, and 1203 c, MFPs 1204,1205 a, 1205 b, 1205 c, and 1205 d, scanners 1206 a and 1206 b, aprinter 1207, and the like, connected one to another through a network.The image formation system shown in FIG. 19 has a configuration whereina network 1201 shown in FIG. 20 is divided into two network systems inorder to improve performance. The two network systems will be referredto as “public network 1201 a” and “private network 1201 b”, hereafter.The image formation system according to the present embodiment may haveeither of the network configurations, so description will be made mainlyregarding the network configuration shown in FIG. 19.

The document server 1202 has two network interface cards (NICs) for thetwo system: one is an NIC 1211 connected to the public network 1201 a;other is an NIC 1212 connected to the private network 1201 b.

The computers 1203 a, 1203 b, and 1203 c are client computers whichtransmit jobs to the document server 1202. Note that a number of clientcomputers (not shown) are further connected other than the computers1203 a through 1203 c. These client computers will be simply referred toas “client computer 1203” hereafter.

MPFs (multiple function peripherals) 1205 and a printer 1207 areconnected to the private network 1201 b. The MFPs 1205 perform scanningand printout in monochrome, or perform scanning and printout with lowresolution in simple color mode of two colors. Note that devices such asscanners, printers, facsimiles (FAX), and the like, (not shown) arefurther connected to the private network 1201 b besides theaforementioned MFPs.

The MPF 1204 is a full-color MPF which can perform scanning and printoutwith high resolution and high contrast in full color. The MFP 1204 hasthe same configuration as with the image formation apparatus describedin the first embodiment, except that the MFP 1204 can be connected to anetwork, so description thereof will be omitted. The MFP 1204 may beconnected to the private network 1201B so as to performtransmission/reception of data, but the amount of data becomes massive,and accordingly, the present embodiment has a configuration whereinmultiple-bit data can be transmitted and received at the same timethrough an independent interface. Thus, the MFP 1204 is connected to thedocument server 1202 through an dedicated interface card 1213.

The scanners 1206 are devices for acquiring image data from the documentsheet, and consist of two types of scanners: one type includes thescanner 1206 a connected to the server 1202 through a SCSI interface;the other type includes the scanner 1206 b connected to the publicnetwork 1201 a. Note that the scanner 1206 b may be connected to theprivate network 1201 b.

The document server 1202 has a hardware configuration wherein the NICs(network interface cards) 1211 and 1212, the dedicated interface card1213, a SCSI (small computer system interface) card 1214, and the like,are mounted on a mother board 1210 where the CPU, memory and the likehave been mounted, through the PCI (peripheral component interconnect)bus.

On the other hand, application software for performing so-called DTP(desk top publishing) is executed on the client computers 1203, wherebyvarious types of documents and pictures are formed and edited. Theclient computers 1203 convert the formed documents and pictures into thePDL data (page description language), and the generated PDL data istransmitted to the MFP 1204 or MFP 1205 through the network 1201 a so asto perform printout.

The MFPs 1204 and 1205 each have communication means (NIC unit andinterface unit, described later) for communicating with the documentserver 1202 through a communication cable 1209 connected to the network1201 b or the dedicated interface 1213. Accordingly, the information orthe state of the MFPs 1204 and 1205 can be transmitted to the clientcomputers 1203 in real time through the document server 1202.

The document server 1202 has utility software for executing according tothe received information, whereby the MFPs 1204 and 1205 are managed bythe server computer 1202. Note that an arrangement may be made whereinthe client computer 1203 has utility software so as to manage the MFPs.

[Operating Display Unit]

FIG. 21 is a diagram which illustrates an external view of an operatingdisplay unit 550 of the MFPs 1204 and 1205. The operating display unit550 shown in FIG. 21 has a similar configuration to that shown in FIG.9, so description regarding the same components will be omitted.

Reference numeral 563 denotes a maintenance key 563. Upon the userpressing the maintenance key 563 in a standby state (ready), the screenshown in FIG. 22 is displayed. Note that the system has a configurationwherein the maintenance key 563 cannot be selected during printout.

[Maintenance Management]

FIG. 22 is a diagram which illustrates a maintenance management screendisplayed on the operation display unit 550. Reference numeral 571denotes a adjustment key for obtaining information with regard to thesituation of each adjustment item. Reference numeral 572 denotes anexpendables key for obtaining information with regard to the consumptionsituation of the expendables. Reference numeral 573 denotes another-printers key for obtaining information with regard to theadjustment situation of other image formation apparatuses connected tothe network.

Upon the user selecting the adjustment key 571, the screen shown in FIG.23 is displayed. FIG. 23 is a diagram which illustrates an adjustmentscreen displayed on the operation display unit 550. In this case, thelist of “adjustment item”, “remaining pages (remaining copies)”, and“adjustment time period” is displayed on the adjustment screen. Here,the adjustment item is performed in order to prevent deviation of colortone from the original image due to various conditions such as thechange in the environment where the image formation apparatus issituated, printout of a number of sheets, or the like. Examples of theadjustment items include the density adjustment, registrationadjustment, and the like. The “remaining copies” means the number ofremaining printing pages wherein the next adjustment item is to beexecuted.

Here, upon the user selecting the item on the touch panel in the standbystate for performing adjustment, the selected adjustment item is hatched(in FIG. 23, a density adjustment item 576 is selected). Subsequently,upon the user pressing an adjustment start key 574, the selectedadjustment mode (automatic adjustment or maintenance) is started.

As described above, the user can confirm the adjustment item wherein theadjustment mode could be started during the next job, in idle timebetween the preceding and next jobs, at the time of turning on the powersupply, or the like. Furthermore, the user can select the mode on thesame screen wherein in the event that there is time till the next job,the adjustment is performed beforehand. Furthermore, the user can selectmultiple adjustment items at the same time, and in this case, theselected multiple adjustment modes can be performed at the same time.For example, the user can select both of the density adjustment and theregistration adjustment for performing both adjustment at the same time.Both the selected adjustment items are hatched, and upon the userpressing the adjustment start key 574, both the adjustment modes areexecuted.

The aforementioned adjustment item is performed following apredetermined number of copies being made after previous execution ofthe adjustment. With the present embodiment, the adjustment items aredisplayed in the order of execution of the adjustment. Note that it isneedless to say that the adjustment items may be displayed in the orderof the length of the adjustment time period.

In the event of performing the density adjustment processing, the imageformation apparatus adjusts the density control bias having an influenceupon the image density, such as a developing bias, exposure amount, orthe like, whereby the image density of the toner image is adjusted to asuitable density. On the other hand, in the event of performing theregistration adjustment processing, registration detection toner images(lines) are formed on the transfer belt 333 for each color as a testpattern, and each transferring position thereof is detected by theregistration sensor 972 (see FIG. 7) so as to adjust the formationtiming of the electrostatic latent image formed by the laser scanningand exposure based upon the detected result. The density adjustmentprocessing and the registration adjustment processing will be describedlater in detail.

On the other hand, in the event of selecting the cleaning adjustment(drum cleaning), an adjustment mode is performed for preventingmalfunctioning of the transfer belt. Note that each image formationapparatus has particular adjustment items, and accordingly, it isneedless to say that the adjustment items according to the presentinvention are not restricted to those shown in the present embodiment.

In FIG. 23, reference numeral 575 denotes a threshold count change keyfor changing the number of copies which can be made from the previousadjustment up to the next adjustment (threshold count number). Forexample, in the event that the user selects the density adjustment item576, the selected item is hatched, and upon the user pressing thethreshold count change key 575, a threshold value change screen shown inFIG. 24 is displayed.

FIG. 24 is a diagram which illustrates the threshold change screendisplayed on the operation display unit 550. The user can change athreshold value counter 592 on the screen. The threshold value counter592 indicates the number of copies (X) which can be made from theprevious adjustment up to the next adjustment, wherein the user caninput a value with the numerical keypad 552. The remaining number ofcopies (Z) which can be made up to the next adjustment is changedsynchronously with the change of the threshold value (X). With thenumber of copies which have been made from the previous adjustment as Y,the number of the remaining copies (Z) which can be made up to the nextadjustment is represented by Expression (3).Z=X−Y  (3)

The changed threshold value is stored in the EEPROM 13. The thresholdvalue is changed in the event of performing adjustment at intervals lessthan the default adjustment interval in order to give priority to theimage quality, or in the event of performing adjustment at longintervals since the image formation apparatus is situated in theenvironment under suitable conditions (temperature, humidity, and thelike) for image formation. On the other hand, upon the user pressing adefault key 591, the threshold value 592 is returned to the defaultvalue (the value at the shipping time).

In the event that the user selects the expendables key 572 on themaintenance management display shown in FIG. 22 in the standby state,the screen shown in FIG. 26 is displayed. FIG. 26 is a diagram whichillustrates a list of expendables displayed on the operation displayunit 550. Here, the user can display the procedure for replacement asfollows. First, upon the user selecting the desired replacement item onthe touch panel, the selected item is hatched. Next, upon the userselecting a procedure display key 583, the procedure for requiredreplacement is displayed. For example, upon the user selecting thestaple-cartridge replacement item in FIG. 26, the selected item ishatched. Subsequently, upon the user pressing the procedure display key583, the procedure for replacement of staples is displayed.

In the event of performing replacement (supply) of the staple-cartridgeprior to being completely out of staples, the user can clear the countvalue by selecting a counter clear key 581. With an example of thepresent embodiment, the staple cartridge stores 5,000 staples.Accordingly, upon the user pressing the counter clear key 581, thenumber of remaining staples is cleared to 5,000.

[Maintenance Management for Other Image Formation Apparatuses]

In the event that the user presses an other-printers key 573 on themaintenance management screen shown in FIG. 22, the screen shown in FIG.25 is displayed. FIG. 25 is a diagram which illustrates a status screendisplayed on the operation display unit 550. The status screen displaysthe status of other image formation apparatuses connected through thenetwork 101, specifically, MPFs 1205 a through 1205 d. With the example,the status of “Ready (standby for printing)” or “Printing (duringprinting)” is displayed for each image formation apparatus.

Other image formation apparatuses (MFPs) displayed on the screen havebeen registered in the image formation apparatus which is being operatedby the user. Here, the user can confirm the adjustment situation(status) of a particular image formation apparatus as follows. First,upon the user selecting an item 593 for a desired image formationapparatus (in FIG. 25, the MFP 1205 a is selected), the item 593 ishatched. Subsequently, upon the user pressing an OK key 594, a similarscreen as shown in FIG. 23 described above is displayed. Note that it isneedless to say that the adjustment items and the number of theremaining copies which can be made up to the next adjustment aredifferent for each image formation apparatus. The screens for confirmingthe status of other image formation apparatuses connected through anetwork have the same configurations shown in FIGS. 24 and 26, sodescription thereof will be omitted. Thus, the user can confirm theadjustment situation (status) of other image formation apparatusconnected through a network, and furthermore, can perform desiredadjustment mode. The adjustment mode has been described in the firstembodiment, so description thereof will be omitted.

[Adjustment Execution Processing]

FIG. 27 is a flowchart which shows steps for adjustment executionprocessing performed at the time of the user selecting the maintenancekey 563 on the operation display unit 550 of the image formationapparatus. The processing program is stored in the ROM 11 within theprinter unit 300, and is executed by the CPU 15.

First, determination is made whether or not the system is in theadjustment mode (Step S501). Note that upon the user pressing theadjustment key 571 shown in FIG. 22, the system enters the adjustmentmode. In the event that determination is made that the system is in theadjustment mode, adjustment information is displayed (Step S502).Examples of adjustment information displayed on the screen includeadjustment items, the number of remaining copies which can be made up tothe next adjustment, and a time period for adjustment, as shown in FIG.23 described above.

Subsequently, determination is made whether or not the user selects anyadjustment items (Step S503). In the event that the user has not selectany adjustment item, determination is made whether or not end ofconfirmation is selected by the user pressing a return key 579 (StepS507). In the event that the return key 579 is not pressed by the user,and accordingly, end of confirmation is not selected, the flow returnsto Step S503, and the same processing is repeated. Otherwise, thepresent processing ends.

On the other hand, in the event that the user has selected anyadjustment item in Step S503, the system waits for the adjustment startkey 574 to be selected (Step S504). That is to say, in the event thatthe adjustment start key 574 has not been selected, determination ismade whether or not end of confirmation has been selected (Step S507).In the event that the return key 579 has not been pressed, i.e., in theevent that end of confirmation has not been selected, the flow returnsto Step S503, and the same processing is repeated.

On the other hand, in the event that the user presses the adjustmentstart key in Step S504, the adjustment mode processing corresponding tothe selected adjustment item (Step S505) is performed. For example, inthe event that the density adjustment has been selected, theabove-described density adjustment processing is performed. In the eventthat multiple adjustment items have been selected, e.g., the densityadjustment and the registration adjustment are selected, theabove-described density adjustment processing and registrationadjustment processing are consecutively performed. The parametersupdated following adjustment are stored in the EEPROM 13.

Following the adjustment processing, the variable Y indicating thenumber of copies which have been made from the previous adjustment up tothe present time is cleared to zero, the updated value is stored in theEEPROM 13 (Step S506), and the present processing ends. At this point intime, the number of remaining copies (Z) which can be made up to thenext adjustment is equal to the threshold. On the other hand, in theevent that the return key 579 is pressed by the user during standby inStep S504, determination is made that end of confirmation has beenselected, and the present processing ends.

As described above, the user can easily confirm the adjustment itemwhich could be performed during the next job in an idle time period upto the next job, at the time of turning on the power supply, or thelike. Furthermore, in the event that there is time till the next job,the user can select the mode wherein the adjustment is performedbeforehand. Furthermore, the user can select multiple adjustment items,whereby multiple adjustment items can be performed at the same time,thereby markedly reducing the downtime during the job due to adjustment.

[Network System]

Next, description will be made regarding a configuration and operationfor managing maintenance for other image formation apparatuses connectedthrough a network. FIG. 28 is a diagram which illustrates aconfiguration of a network system. The networks 1201 (1201 a, 1201 b)are connected through a device for connecting networks one to another,which is referred to as “router”, and forms a further network which isreferred to as “LAN (local area network). A router 1401 within a LAN1406 is connected to another router 1405 within another LAN 1407 througha dedicated line, and in the same way, a great number of networks formsa massive network.

FIG. 29 is a diagram for describing data transmitted on the network1201. Let us say that a device A (1420 a) which transmits data has data1421. The data may be image data, PDL data, or a program. In the eventof transmitting the data to a device B (1420B) through the network 1201,the data 1421 is subdivided into small data units as with data 1422shown in FIG. 29.

The system adds header 1425 including the destination address and thelike to each of subdivided data units 1423, 1424, 1426, and so on, so asto form packets, (e.g., packet 1427 in FIG. 29), and the generatedpackets are transmitted consecutively on the network 1201. Here, in theevent of using the TCP/IP (Transmission Control Protocol/InternetProtocol), the IP address of the destination is used as a destinationaddress. In the event that the header 1431 of the packet 1430 matchesthe address of the device B, the data 1432 is separated in the device Bso as to be reproduced into the same data as the original data in thedevice A.

[Printer Driver]

FIG. 30 is a diagram which illustrates a screen of a printer driver.With the example, image data is transmitted to a printer from thedocument server 1202 and the computer 1203 through the printer driver.The printer driver is a GUI for specifying printing operation, whereinthe user can specify desired setting parameters and transmit desiredimage data to a destination such as a printer, by operating the GUI onthe screen.

Reference numeral 1601 denotes a window of the printer driver. Referencenumeral 1602 denotes a destination selecting column in the window forselecting the destination where the data is to be transmitted. With theexample, the destination is selected from the MFPs 1204 and 1205, andthe printer 1207. Reference numeral 1603 denotes a page setting columnfor determining which pages of the image formed by application softwareoperating on the document server 1202 or the computer 1203 are output.

Reference numeral 1604 denotes a number-of-copies setting column forspecifying the number of copies. Reference numeral 1607 denotes aproperty key for making detailed settings for the destination deviceselected with the destination selecting column 1602. In the event thatuser clicks the property key 1607, another screen is displayed, whereinthe user can input device-specific setting information on the screen soas to perform special image processing. For example, the user can changethe parameters of a gamma conversion unit or a spatial filter unitwithin the printer. This enables more detailed color reproduction orsharpness adjustment. Following desired settings being made, upon theuser pressing an OK key 1605, printout is started. The user can cancelthe printout by pressing a cancel key 1606.

[Operation with Web Browser]

FIG. 31 is a diagram which illustrates a main screen of a web serviceprovided within the document server 1202. The system has a configurationwherein upon the user inputting the IP address of the server 1202 (withthe example of the present embodiment, 192.168.100.11) in a URL addressportion, the web service screen is read out from the server 1202 to bedisplayed.

The service tool is formed of tabs of a job status tab 1701, a devicestatus tab 1702, a job submitting tab 1703, a scanning tab 1704, aconfiguration tab 1705, and a help tab 1706, and a maintenance statuskey 1712. The help tab 1706 includes a manual for the present service.

[Job Status]

The job status tab 1701 is formed of a device display portion 1707, ajob status display portion 1709 for displaying active jobs, and a jobhistory display portion 1711. In the event that all the jobs cannot bedisplayed on the job status display portion 1709 or the job historydisplay portion 1711, upon the user pressing the job status key 1708 asnecessary, all the active jobs are displayed. Furthermore, upon the userpressing a job history key 1710, all the job history is displayed.

FIG. 32 is a diagram which illustrates a device display portion 1707.With the example, device names 1721 through 1724, device icons 1725through 1728, and the status information 1729 through 1732 for eachdevice, are displayed. Here, the device icons are changed according tothe status (see device icons 1728 and 1728). As described above, theuser can confirm the status of each device from the change in the deviceicons 1725 through 1728, and from the character information of thestatus information 1729 through 1728.

FIG. 33 is a diagram which illustrates a job status display portion1709. The user can monitor the status of each job within the server 1202on the job status display portion 1709. For example, the job status suchas “Spooling” (during reception of data prior to RIP), “Ripping” (duringRIP), “Wait to Print” (waiting for printing), or “Printing” (duringprinting), is displayed. A job which is instructed to wait within theserver at the time of the job being input is held with the status priorto RIP. In the event that error or jamming occurs, information thereofis displayed so as to alert the user. Following printout, the job istransmitted to the next finished job. Furthermore, other items such asjob names 1741, target printers 1742, job priorities 1744, and the like,are displayed on the job status display portion 1709 for active jobs.

FIG. 34 is a diagram which illustrates the job history display portion1711. The user can obtain information with regard to the history of jobsfrom the job history display portion 1711. In the event that the job hasbeen completed normally, “Printed” is displayed. On the other hand, inthe event that the job has been canceled during printout, “Canceled” isdisplayed. Furthermore, other items such as job names 1761, targetprinters 1762, job IDs 1764, and the like, are displayed on the jobhistory display portion 1711. The user operates the server 1202 basedupon the above-described information.

[Device Status]

A standardized database which is referred to as “MIB” (managementinformation base) is built in the network interface within the MFPs 1204and 1205, and the printer 1207. The MIB communicates with computers on anetwork following the network management protocol which is referred toas “SNMP” (Simple Network Management Protocol), thereby enablinginterchange of necessary information with regard to the status of thedevice connected to the network, such as the MFP 1204, MFP 1205, or thelike, with the computers 1202 and 1203.

For example, the user can detect information with regard to functions ofthe finisher 400 as equipment information for the MFPs 1204 and 1205,the presence or absence of error and jamming, and information whetherthe job is during printout or in idle. Furthermore, the user can obtainall the stationary information such as maintenance status for each MFP,equipment information for the MFPs 1204 and 1205, the status of theapparatus, settings of the network, job history, management and controlof the status of use, and the like.

FIG. 35 is a diagram which illustrates the device status tab 1702. Onthe tab, the size of sheets stored in a sheet cassette mounted within adevice managed by the server 1202, and status of supply of sheets, aredisplayed. The user can confirm the sheet size, the status of supply1801 through 1806, and status of accessories 1807 such as a finishermounted to each device, beforehand.

Furthermore, the document server 1202 can give adjustment instructionsrequired for the device as to the device connected through the network1201 by the user selecting the maintenance key 1712. That is to say,upon the user pressing the maintenance key 1712, a screen similar to thescreen shown in FIG. 25 described above is loaded. The detaileddescription thereof is generally the same as with the descriptionregarding the operation display unit 550, so the detailed descriptionwill be omitted. In brief, the system has a configuration wherein theuser can confirm the adjustment status for each MFP on the documentserver 1202, and can make desired adjustment instructions.

[Adjustment Execution Processing for Other MFPs]

FIG. 36 is a flowchart which shows steps for adjustment executionprocessing at the time of executing the adjustment mode following theinstructions from other image formation apparatuses connected to thenetwork. Here, an example is shown wherein the MFP 1205 a performsadjustment mode following instructions from the different MFP 1204 orthe server 1202 connected to the network 1201.

That is to say, an example is shown wherein adjustment instructions aregiven to the MFP 1205 a from the operation display unit 550 of the MFP1204 or the maintenance key 1712 on the web service of the documentserver 1202. The processing is stored in the ROM 11 within the printerunit 300, and is executed by the CPU 15 as with the processing shown inFIG. 27.

First, the system waits for the MFP 1205 a to be in the standby state(Step S611). In the event that the MFP 1205 a is standing by,determination is made whether or not the MFP 1205 a has receivedadjustment instructions from an external unit connected to the network1201, e.g., the MFP 1204 or server 1202 (Step S612). In the event thatdetermination is made that the MFP 1205 a has received adjustmentinstructions, the MFP 1205 a analyzes the adjustment instructions, andperforms specified adjustment mode (Step S613). The adjustment mode inthis example is the same as in FIG. 27 described above, so descriptionthereof will be omitted.

Following the adjustment processing, the variable Y indicating thenumber of copies which have been made from the previous adjustment up tothe present time is cleared to zero, and the updated value is stored inthe EEPROM 13 (Step S614). At this point in time, the number ofremaining copies Z which can be made up to the next adjustment is equalto the threshold.

As described above, with the present embodiment, multiple MFPs areconnected through a network, and accordingly, the user can easilyconfirm the adjustment item of any MFP, which could be performed duringthe next job, and can give required adjustment instructions to the MFP.The user can give adjustment instructions from one MFP to another MFPconnected to the network, and thus, even in the event that MFPs aredistant one from another, the user can perform adjustment for thedistant MFP without the user moving to the distant MFP.

While description has been made above regarding the embodiments of thepresent invention, the present invention is not restricted to theseembodiments, but rather, the present invention may be applied to anyconfiguration as long as the configuration satisfies any of the appendedclaims or any of the embodiments.

For example, while the density adjustment and registration adjustmenthave been shown as examples of the items of the maintenance in theabove-described embodiments, actual maintenance includes more variousitems. Furthermore, the maintenance according to the present inventionshould be understood in the broad sense, and encompasses not onlyadjustment of the component, which means maintenance in the generalsense, but also cleaning, replacement and supply of expendables, and thelike.

FIGS. 37 through 39 are diagrams showing item list of the maintenance.The maintenance items described in the item list and the relatedinformation are registered in the ROM 11 within the MFP, for example,and can be read out by the CPU 15. Specifically, the item of themaintenance, the type thereof, the standard of judgment, and theestimated required time period (estimated time period), are listed inthe item list. As examples of types of maintenance, replacement ofexpendables and regular cleaning are shown. Furthermore, the outputvalue from the sensor or the count value from the counter (time, copies)is used for making determination whether or not maintenance should bemade. Examples of the output value from the sensor include detectedvalue of the status of toner, sheets, or the like. Examples of the countvalue include the number wherein the number of copies which have beenmade is subtracted from the number of the threshold, and the remainingtime wherein the elapsed time is subtracted from the setting time. Notethat the items of the estimated time period which is difficult to beestimated are left blank.

While the present invention has been described with reference to whatare presently considered to be the preferred embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments. On the contrary, the invention is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims. The scope of the following claims is to beaccorded the broadest interpretation so as to encompass all suchmodifications and equivalent structures and functions.

1. An image formation apparatus for forming images based on input imagedata, said apparatus comprising: an automatic adjustment portion adaptedto perform automatic adjustment of said image formation apparatus foreach of a plurality of adjustment items; a counting portion adapted tocount the number of image formation pages from a last automaticadjustment, for each automatic adjustment item which said automaticadjustment portion performs; a control portion adapted to effectautomatic adjustment by an automatic adjustment portion, in response tothe number of image formation pages counted by said counting portion,reaching a first threshold value; a setting portion adapted to set, foreach of the plurality of adjustment items, a second threshold value lessthan the first threshold value; and a determining portion adapted todetermine, for each of the plurality of adjustment items, whether thenumber of image formation pages counted by said counting portion havereached the second threshold value set by said setting portion, beforestarting execution of the next image formation job, wherein, in theevent that said determining portion determines that there is at least anadjustment item for which the number of image formation pages counted bysaid counting portion have reached the second threshold value, saidcontrol portion effects automatic adjustment by said automaticadjustment portion before starting execution of the next image formationjob, even though the number of image formation pages counted by saidcounting portion has not reached the first threshold value, and whereinthe second threshold value is automatically determined based on anaverage number of image formation sheets per job, within a predeterminedperiod or within a predetermined number of times of image formationjobs.
 2. An image formation apparatus according to claim 1, wherein theplurality of adjustment items includes at least density adjustment,which forms an image for density detection and determines density of theimage for density detection, and registration adjustment, which forms animage for position detection and determines a position of the image forposition detection, and at least one other adjustment item.
 3. An imageformation apparatus according to claim 2, wherein the at least one otheradjustment item is cleaning adjustment.